<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/x86/kernel/apic, branch v3.14.37</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>x86, apic: Handle a bad TSC more gracefully</title>
<updated>2014-11-14T17:00:10+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2014-10-15T17:12:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=09eea6d2a92e092897d6767988e21186d2ed781e'/>
<id>09eea6d2a92e092897d6767988e21186d2ed781e</id>
<content type='text'>
commit b47dcbdc5161d3d5756f430191e2840d9b855492 upstream.

If the TSC is unusable or disabled, then this patch fixes:

 - Confusion while trying to clear old APIC interrupts.
 - Division by zero and incorrect programming of the TSC deadline
   timer.

This fixes boot if the CPU has a TSC deadline timer but a missing or
broken TSC.  The failure to boot can be observed with qemu using
-cpu qemu64,-tsc,+tsc-deadline

This also happens to me in nested KVM for unknown reasons.
With this patch, I can boot cleanly (although without a TSC).

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Bandan Das &lt;bsd@redhat.com&gt;
Link: http://lkml.kernel.org/r/e2fa274e498c33988efac0ba8b7e3120f7f92d78.1413393027.git.luto@amacapital.net
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b47dcbdc5161d3d5756f430191e2840d9b855492 upstream.

If the TSC is unusable or disabled, then this patch fixes:

 - Confusion while trying to clear old APIC interrupts.
 - Division by zero and incorrect programming of the TSC deadline
   timer.

This fixes boot if the CPU has a TSC deadline timer but a missing or
broken TSC.  The failure to boot can be observed with qemu using
-cpu qemu64,-tsc,+tsc-deadline

This also happens to me in nested KVM for unknown reasons.
With this patch, I can boot cleanly (although without a TSC).

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Bandan Das &lt;bsd@redhat.com&gt;
Link: http://lkml.kernel.org/r/e2fa274e498c33988efac0ba8b7e3120f7f92d78.1413393027.git.luto@amacapital.net
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-01-31T16:59:46+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-01-31T16:59:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ab5318788c6725b6d5c95aff28e63af4c35a0e2c'/>
<id>ab5318788c6725b6d5c95aff28e63af4c35a0e2c</id>
<content type='text'>
Pull core debug changes from Ingo Molnar:
 "This contains mostly kernel debugging related updates:

   - make hung_task detection more configurable to distros
   - add final bits for x86 UV NMI debugging, with related KGDB changes
   - update the mailing-list of MAINTAINERS entries I'm involved with"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hung_task: Display every hung task warning
  sysctl: Add neg_one as a standard constraint
  x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured
  x86/uv/nmi: Fix Sparse warnings
  kgdb/kdb: Fix no KDB config problem
  MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull core debug changes from Ingo Molnar:
 "This contains mostly kernel debugging related updates:

   - make hung_task detection more configurable to distros
   - add final bits for x86 UV NMI debugging, with related KGDB changes
   - update the mailing-list of MAINTAINERS entries I'm involved with"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hung_task: Display every hung task warning
  sysctl: Add neg_one as a standard constraint
  x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured
  x86/uv/nmi: Fix Sparse warnings
  kgdb/kdb: Fix no KDB config problem
  MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/uv/nmi: Fix Sparse warnings</title>
<updated>2014-01-25T07:55:10+00:00</updated>
<author>
<name>Mike Travis</name>
<email>travis@sgi.com</email>
</author>
<published>2014-01-14T16:25:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=74c93f9d39b556ff9ac2340d568ad5caf8446c65'/>
<id>74c93f9d39b556ff9ac2340d568ad5caf8446c65</id>
<content type='text'>
Make uv_register_nmi_notifier() and uv_handle_nmi_ping() static
to address sparse warnings.

Fix problem where uv_nmi_kexec_failed is unused when
CONFIG_KEXEC is not defined.

Signed-off-by: Mike Travis &lt;travis@sgi.com&gt;
Reviewed-by: Hedi Berriche &lt;hedi@sgi.com&gt;
Cc: Russ Anderson &lt;rja@sgi.com&gt;
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@ghostprotocols.net&gt;
Link: http://lkml.kernel.org/r/20140114162551.480872353@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make uv_register_nmi_notifier() and uv_handle_nmi_ping() static
to address sparse warnings.

Fix problem where uv_nmi_kexec_failed is unused when
CONFIG_KEXEC is not defined.

Signed-off-by: Mike Travis &lt;travis@sgi.com&gt;
Reviewed-by: Hedi Berriche &lt;hedi@sgi.com&gt;
Cc: Russ Anderson &lt;rja@sgi.com&gt;
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@ghostprotocols.net&gt;
Link: http://lkml.kernel.org/r/20140114162551.480872353@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2014-01-24T23:51:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-01-24T23:51:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=09da8dfa98682d871987145ed11e3232accac860'/>
<id>09da8dfa98682d871987145ed11e3232accac860</id>
<content type='text'>
Pull ACPI and power management updates from Rafael Wysocki:
 "As far as the number of commits goes, the top spot belongs to ACPI
  this time with cpufreq in the second position and a handful of PM
  core, PNP and cpuidle updates.  They are fixes and cleanups mostly, as
  usual, with a couple of new features in the mix.

  The most visible change is probably that we will create struct
  acpi_device objects (visible in sysfs) for all devices represented in
  the ACPI tables regardless of their status and there will be a new
  sysfs attribute under those objects allowing user space to check that
  status via _STA.

  Consequently, ACPI device eject or generally hot-removal will not
  delete those objects, unless the table containing the corresponding
  namespace nodes is unloaded, which is extremely rare.  Also ACPI
  container hotplug will be handled quite a bit differently and cpufreq
  will support CPU boost ("turbo") generically and not only in the
  acpi-cpufreq driver.

  Specifics:

   - ACPI core changes to make it create a struct acpi_device object for
     every device represented in the ACPI tables during all namespace
     scans regardless of the current status of that device.  In
     accordance with this, ACPI hotplug operations will not delete those
     objects, unless the underlying ACPI tables go away.

   - On top of the above, new sysfs attribute for ACPI device objects
     allowing user space to check device status by triggering the
     execution of _STA for its ACPI object.  From Srinivas Pandruvada.

   - ACPI core hotplug changes reducing code duplication, integrating
     the PCI root hotplug with the core and reworking container hotplug.

   - ACPI core simplifications making it use ACPI_COMPANION() in the
     code "glueing" ACPI device objects to "physical" devices.

   - ACPICA update to upstream version 20131218.  This adds support for
     the DBG2 and PCCT tables to ACPICA, fixes some bugs and improves
     debug facilities.  From Bob Moore, Lv Zheng and Betty Dall.

   - Init code change to carry out the early ACPI initialization
     earlier.  That should allow us to use ACPI during the timekeeping
     initialization and possibly to simplify the EFI initialization too.
     From Chun-Yi Lee.

   - Clenups of the inclusions of ACPI headers in many places all over
     from Lv Zheng and Rashika Kheria (work in progress).

   - New helper for ACPI _DSM execution and rework of the code in
     drivers that uses _DSM to execute it via the new helper.  From
     Jiang Liu.

   - New Win8 OSI blacklist entries from Takashi Iwai.

   - Assorted ACPI fixes and cleanups from Al Stone, Emil Goode, Hanjun
     Guo, Lan Tianyu, Masanari Iida, Oliver Neukum, Prarit Bhargava,
     Rashika Kheria, Tang Chen, Zhang Rui.

   - intel_pstate driver updates, including proper Baytrail support,
     from Dirk Brandewie and intel_pstate documentation from Ramkumar
     Ramachandra.

   - Generic CPU boost ("turbo") support for cpufreq from Lukasz
     Majewski.

   - powernow-k6 cpufreq driver fixes from Mikulas Patocka.

   - cpufreq core fixes and cleanups from Viresh Kumar, Jane Li, Mark
     Brown.

   - Assorted cpufreq drivers fixes and cleanups from Anson Huang, John
     Tobias, Paul Bolle, Paul Walmsley, Sachin Kamat, Shawn Guo, Viresh
     Kumar.

   - cpuidle cleanups from Bartlomiej Zolnierkiewicz.

   - Support for hibernation APM events from Bin Shi.

   - Hibernation fix to avoid bringing up nonboot CPUs with ACPI EC
     disabled during thaw transitions from Bjørn Mork.

   - PM core fixes and cleanups from Ben Dooks, Leonardo Potenza, Ulf
     Hansson.

   - PNP subsystem fixes and cleanups from Dmitry Torokhov, Levente
     Kurusa, Rashika Kheria.

   - New tool for profiling system suspend from Todd E Brandt and a
     cpupower tool cleanup from One Thousand Gnomes"

* tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (153 commits)
  thermal: exynos: boost: Automatic enable/disable of BOOST feature (at Exynos4412)
  cpufreq: exynos4x12: Change L0 driver data to CPUFREQ_BOOST_FREQ
  Documentation: cpufreq / boost: Update BOOST documentation
  cpufreq: exynos: Extend Exynos cpufreq driver to support boost
  cpufreq / boost: Kconfig: Support for software-managed BOOST
  acpi-cpufreq: Adjust the code to use the common boost attribute
  cpufreq: Add boost frequency support in core
  intel_pstate: Add trace point to report internal state.
  cpufreq: introduce cpufreq_generic_get() routine
  ARM: SA1100: Create dummy clk_get_rate() to avoid build failures
  cpufreq: stats: create sysfs entries when cpufreq_stats is a module
  cpufreq: stats: free table and remove sysfs entry in a single routine
  cpufreq: stats: remove hotplug notifiers
  cpufreq: stats: handle cpufreq_unregister_driver() and suspend/resume properly
  cpufreq: speedstep: remove unused speedstep_get_state
  platform: introduce OF style 'modalias' support for platform bus
  PM / tools: new tool for suspend/resume performance optimization
  ACPI: fix module autoloading for ACPI enumerated devices
  ACPI: add module autoloading support for ACPI enumerated devices
  ACPI: fix create_modalias() return value handling
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ACPI and power management updates from Rafael Wysocki:
 "As far as the number of commits goes, the top spot belongs to ACPI
  this time with cpufreq in the second position and a handful of PM
  core, PNP and cpuidle updates.  They are fixes and cleanups mostly, as
  usual, with a couple of new features in the mix.

  The most visible change is probably that we will create struct
  acpi_device objects (visible in sysfs) for all devices represented in
  the ACPI tables regardless of their status and there will be a new
  sysfs attribute under those objects allowing user space to check that
  status via _STA.

  Consequently, ACPI device eject or generally hot-removal will not
  delete those objects, unless the table containing the corresponding
  namespace nodes is unloaded, which is extremely rare.  Also ACPI
  container hotplug will be handled quite a bit differently and cpufreq
  will support CPU boost ("turbo") generically and not only in the
  acpi-cpufreq driver.

  Specifics:

   - ACPI core changes to make it create a struct acpi_device object for
     every device represented in the ACPI tables during all namespace
     scans regardless of the current status of that device.  In
     accordance with this, ACPI hotplug operations will not delete those
     objects, unless the underlying ACPI tables go away.

   - On top of the above, new sysfs attribute for ACPI device objects
     allowing user space to check device status by triggering the
     execution of _STA for its ACPI object.  From Srinivas Pandruvada.

   - ACPI core hotplug changes reducing code duplication, integrating
     the PCI root hotplug with the core and reworking container hotplug.

   - ACPI core simplifications making it use ACPI_COMPANION() in the
     code "glueing" ACPI device objects to "physical" devices.

   - ACPICA update to upstream version 20131218.  This adds support for
     the DBG2 and PCCT tables to ACPICA, fixes some bugs and improves
     debug facilities.  From Bob Moore, Lv Zheng and Betty Dall.

   - Init code change to carry out the early ACPI initialization
     earlier.  That should allow us to use ACPI during the timekeeping
     initialization and possibly to simplify the EFI initialization too.
     From Chun-Yi Lee.

   - Clenups of the inclusions of ACPI headers in many places all over
     from Lv Zheng and Rashika Kheria (work in progress).

   - New helper for ACPI _DSM execution and rework of the code in
     drivers that uses _DSM to execute it via the new helper.  From
     Jiang Liu.

   - New Win8 OSI blacklist entries from Takashi Iwai.

   - Assorted ACPI fixes and cleanups from Al Stone, Emil Goode, Hanjun
     Guo, Lan Tianyu, Masanari Iida, Oliver Neukum, Prarit Bhargava,
     Rashika Kheria, Tang Chen, Zhang Rui.

   - intel_pstate driver updates, including proper Baytrail support,
     from Dirk Brandewie and intel_pstate documentation from Ramkumar
     Ramachandra.

   - Generic CPU boost ("turbo") support for cpufreq from Lukasz
     Majewski.

   - powernow-k6 cpufreq driver fixes from Mikulas Patocka.

   - cpufreq core fixes and cleanups from Viresh Kumar, Jane Li, Mark
     Brown.

   - Assorted cpufreq drivers fixes and cleanups from Anson Huang, John
     Tobias, Paul Bolle, Paul Walmsley, Sachin Kamat, Shawn Guo, Viresh
     Kumar.

   - cpuidle cleanups from Bartlomiej Zolnierkiewicz.

   - Support for hibernation APM events from Bin Shi.

   - Hibernation fix to avoid bringing up nonboot CPUs with ACPI EC
     disabled during thaw transitions from Bjørn Mork.

   - PM core fixes and cleanups from Ben Dooks, Leonardo Potenza, Ulf
     Hansson.

   - PNP subsystem fixes and cleanups from Dmitry Torokhov, Levente
     Kurusa, Rashika Kheria.

   - New tool for profiling system suspend from Todd E Brandt and a
     cpupower tool cleanup from One Thousand Gnomes"

* tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (153 commits)
  thermal: exynos: boost: Automatic enable/disable of BOOST feature (at Exynos4412)
  cpufreq: exynos4x12: Change L0 driver data to CPUFREQ_BOOST_FREQ
  Documentation: cpufreq / boost: Update BOOST documentation
  cpufreq: exynos: Extend Exynos cpufreq driver to support boost
  cpufreq / boost: Kconfig: Support for software-managed BOOST
  acpi-cpufreq: Adjust the code to use the common boost attribute
  cpufreq: Add boost frequency support in core
  intel_pstate: Add trace point to report internal state.
  cpufreq: introduce cpufreq_generic_get() routine
  ARM: SA1100: Create dummy clk_get_rate() to avoid build failures
  cpufreq: stats: create sysfs entries when cpufreq_stats is a module
  cpufreq: stats: free table and remove sysfs entry in a single routine
  cpufreq: stats: remove hotplug notifiers
  cpufreq: stats: handle cpufreq_unregister_driver() and suspend/resume properly
  cpufreq: speedstep: remove unused speedstep_get_state
  platform: introduce OF style 'modalias' support for platform bus
  PM / tools: new tool for suspend/resume performance optimization
  ACPI: fix module autoloading for ACPI enumerated devices
  ACPI: add module autoloading support for ACPI enumerated devices
  ACPI: fix create_modalias() return value handling
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-01-20T20:03:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-01-20T20:03:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2a0fede97fd52a5c9789d1d54ebd3b46878151c3'/>
<id>2a0fede97fd52a5c9789d1d54ebd3b46878151c3</id>
<content type='text'>
Pull x86 cleanups from Ingo Molnar:
 "Misc cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpu, amd: Fix a shadowed variable situation
  um, x86: Fix vDSO build
  x86: Delete non-required instances of include &lt;linux/init.h&gt;
  x86, realmode: Pointer walk cleanups, pull out invariant use of __pa()
  x86/traps: Clean up error exception handler definitions
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 cleanups from Ingo Molnar:
 "Misc cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpu, amd: Fix a shadowed variable situation
  um, x86: Fix vDSO build
  x86: Delete non-required instances of include &lt;linux/init.h&gt;
  x86, realmode: Pointer walk cleanups, pull out invariant use of __pa()
  x86/traps: Clean up error exception handler definitions
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-01-20T19:50:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-01-20T19:50:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1a7dbbcc8cc6b34f3a4ae92026759fc057ffcba2'/>
<id>1a7dbbcc8cc6b34f3a4ae92026759fc057ffcba2</id>
<content type='text'>
Pull x86/apic changes from Ingo Molnar:
 "Two main changes:

   - improve local APIC Error Status Register reporting robustness

   - add the 'disable_cpu_apicid=x' boot parameter for kexec booting"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, apic: Make disabled_cpu_apicid static read_mostly, fix typos
  x86, apic, kexec: Add disable_cpu_apicid kernel parameter
  x86/apic: Read Error Status Register correctly
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86/apic changes from Ingo Molnar:
 "Two main changes:

   - improve local APIC Error Status Register reporting robustness

   - add the 'disable_cpu_apicid=x' boot parameter for kexec booting"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, apic: Make disabled_cpu_apicid static read_mostly, fix typos
  x86, apic, kexec: Add disable_cpu_apicid kernel parameter
  x86/apic: Read Error Status Register correctly
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, apic: Make disabled_cpu_apicid static read_mostly, fix typos</title>
<updated>2014-01-15T21:02:08+00:00</updated>
<author>
<name>H. Peter Anvin</name>
<email>hpa@zytor.com</email>
</author>
<published>2014-01-15T21:02:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5b4d1dbc24bb6fd7179ada0f47be34e27e64decb'/>
<id>5b4d1dbc24bb6fd7179ada0f47be34e27e64decb</id>
<content type='text'>
Make disabled_cpu_apicid static and read_mostly, and fix a couple of
typos.

Reported-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: http://lkml.kernel.org/r/20140115182511.GA22737@gmail.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: HATAYAMA Daisuke &lt;d.hatayama@jp.fujitsu.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make disabled_cpu_apicid static and read_mostly, and fix a couple of
typos.

Reported-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: http://lkml.kernel.org/r/20140115182511.GA22737@gmail.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: HATAYAMA Daisuke &lt;d.hatayama@jp.fujitsu.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, apic, kexec: Add disable_cpu_apicid kernel parameter</title>
<updated>2014-01-15T17:19:20+00:00</updated>
<author>
<name>HATAYAMA Daisuke</name>
<email>d.hatayama@jp.fujitsu.com</email>
</author>
<published>2014-01-15T06:44:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=151e0c7de616310f95393d9306903900fcd8b277'/>
<id>151e0c7de616310f95393d9306903900fcd8b277</id>
<content type='text'>
Add disable_cpu_apicid kernel parameter. To use this kernel parameter,
specify an initial APIC ID of the corresponding CPU you want to
disable.

This is mostly used for the kdump 2nd kernel to disable BSP to wake up
multiple CPUs without causing system reset or hang due to sending INIT
from AP to BSP.

Kdump users first figure out initial APIC ID of the BSP, CPU0 in the
1st kernel, for example from /proc/cpuinfo and then set up this kernel
parameter for the 2nd kernel using the obtained APIC ID.

However, doing this procedure at each boot time manually is awkward,
which should be automatically done by user-land service scripts, for
example, kexec-tools on fedora/RHEL distributions.

This design is more flexible than disabling BSP in kernel boot time
automatically in that in kernel boot time we have no choice but
referring to ACPI/MP table to obtain initial APIC ID for BSP, meaning
that the method is not applicable to the systems without such BIOS
tables.

One assumption behind this design is that users get initial APIC ID of
the BSP in still healthy state and so BSP is uniquely kept in
CPU0. Thus, through the kernel parameter, only one initial APIC ID can
be specified.

In a comparison with disabled_cpu_apicid, we use read_apic_id(), not
boot_cpu_physical_apicid, because on some platforms, the variable is
modified to the apicid reported as BSP through MP table and this
function is executed with the temporarily modified
boot_cpu_physical_apicid. As a result, disabled_cpu_apicid kernel
parameter doesn't work well for apicids of APs.

Fixing the wrong handling of boot_cpu_physical_apicid requires some
reviews and tests beyond some platforms and it could take some
time. The fix here is a kind of workaround to focus on the main topic
of this patch.

Signed-off-by: HATAYAMA Daisuke &lt;d.hatayama@jp.fujitsu.com&gt;
Link: http://lkml.kernel.org/r/20140115064458.1545.38775.stgit@localhost6.localdomain6
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add disable_cpu_apicid kernel parameter. To use this kernel parameter,
specify an initial APIC ID of the corresponding CPU you want to
disable.

This is mostly used for the kdump 2nd kernel to disable BSP to wake up
multiple CPUs without causing system reset or hang due to sending INIT
from AP to BSP.

Kdump users first figure out initial APIC ID of the BSP, CPU0 in the
1st kernel, for example from /proc/cpuinfo and then set up this kernel
parameter for the 2nd kernel using the obtained APIC ID.

However, doing this procedure at each boot time manually is awkward,
which should be automatically done by user-land service scripts, for
example, kexec-tools on fedora/RHEL distributions.

This design is more flexible than disabling BSP in kernel boot time
automatically in that in kernel boot time we have no choice but
referring to ACPI/MP table to obtain initial APIC ID for BSP, meaning
that the method is not applicable to the systems without such BIOS
tables.

One assumption behind this design is that users get initial APIC ID of
the BSP in still healthy state and so BSP is uniquely kept in
CPU0. Thus, through the kernel parameter, only one initial APIC ID can
be specified.

In a comparison with disabled_cpu_apicid, we use read_apic_id(), not
boot_cpu_physical_apicid, because on some platforms, the variable is
modified to the apicid reported as BSP through MP table and this
function is executed with the temporarily modified
boot_cpu_physical_apicid. As a result, disabled_cpu_apicid kernel
parameter doesn't work well for apicids of APs.

Fixing the wrong handling of boot_cpu_physical_apicid requires some
reviews and tests beyond some platforms and it could take some
time. The fix here is a kind of workaround to focus on the main topic
of this patch.

Signed-off-by: HATAYAMA Daisuke &lt;d.hatayama@jp.fujitsu.com&gt;
Link: http://lkml.kernel.org/r/20140115064458.1545.38775.stgit@localhost6.localdomain6
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic: Read Error Status Register correctly</title>
<updated>2014-01-14T13:05:36+00:00</updated>
<author>
<name>Richard Weinberger</name>
<email>richard@nod.at</email>
</author>
<published>2014-01-14T07:44:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=60283df7ac26a4fe2d56631ca2946e04725e7eaf'/>
<id>60283df7ac26a4fe2d56631ca2946e04725e7eaf</id>
<content type='text'>
Currently we do a read, a dummy write and a final read to fetch
the error code. The value from the final read is taken.
This is not the recommended way and leads to corrupted/lost ESR
values.

Intel(c) 64 and IA-32 Architectures Software Developer's Manual,
Combined Volumes 1, 2ABC, 3ABC, Section 10.5.3 states:

  Before attempt to read from the ESR, software should first
  write to it. (The value written does not affect the values read
  subsequently; only zero may be written in x2APIC mode.) This
  write clears any previously logged errors and updates the ESR
  with any errors detected since the last write to the ESR.
  This write also rearms the APIC error interrupt triggering
  mechanism.

This patch removes the first read such that we are conform with
the manual.

On my (very old) Pentium MMX SMP system this patch fixes the
issue that APIC errors:

  a) are not always reported and
  b) are reported with false error numbers.

Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
Cc: seiji.aguchi@hds.com
Cc: rientjes@google.com
Cc: konrad.wilk@oracle.com
Cc: bp@alien8.de
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Link: http://lkml.kernel.org/r/1389685487-20872-1-git-send-email-richard@nod.at
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently we do a read, a dummy write and a final read to fetch
the error code. The value from the final read is taken.
This is not the recommended way and leads to corrupted/lost ESR
values.

Intel(c) 64 and IA-32 Architectures Software Developer's Manual,
Combined Volumes 1, 2ABC, 3ABC, Section 10.5.3 states:

  Before attempt to read from the ESR, software should first
  write to it. (The value written does not affect the values read
  subsequently; only zero may be written in x2APIC mode.) This
  write clears any previously logged errors and updates the ESR
  with any errors detected since the last write to the ESR.
  This write also rearms the APIC error interrupt triggering
  mechanism.

This patch removes the first read such that we are conform with
the manual.

On my (very old) Pentium MMX SMP system this patch fixes the
issue that APIC errors:

  a) are not always reported and
  b) are reported with false error numbers.

Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
Cc: seiji.aguchi@hds.com
Cc: rientjes@google.com
Cc: konrad.wilk@oracle.com
Cc: bp@alien8.de
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Link: http://lkml.kernel.org/r/1389685487-20872-1-git-send-email-richard@nod.at
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/irq: Fix kbuild warning in smp_irq_move_cleanup_interrupt()</title>
<updated>2014-01-13T14:08:37+00:00</updated>
<author>
<name>Prarit Bhargava</name>
<email>prarit@redhat.com</email>
</author>
<published>2014-01-13T13:40:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c7a730fa4624092e2d1c0cb7b750816e87c32364'/>
<id>c7a730fa4624092e2d1c0cb7b750816e87c32364</id>
<content type='text'>
Fengguang Wu's 0day kernel build service reported the following build warning:

  arch/x86/kernel/apic/io_apic.c:2211
  smp_irq_move_cleanup_interrupt() warn: always true condition '(irq &lt;= -1) =&gt; (0-u32max &lt;= (-1))'

because irq is defined as an unsigned int instead of an int.
Fix this trivial error by redefining irq as a signed int.  The
remaining consumers of the int are okay.

Signed-off-by: Prarit Bhargava &lt;prarit@redhat.com&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Cc: Sebastian Andrzej Siewior &lt;sebastian@breakpoint.cc&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Link: http://lkml.kernel.org/r/1389620420-7110-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fengguang Wu's 0day kernel build service reported the following build warning:

  arch/x86/kernel/apic/io_apic.c:2211
  smp_irq_move_cleanup_interrupt() warn: always true condition '(irq &lt;= -1) =&gt; (0-u32max &lt;= (-1))'

because irq is defined as an unsigned int instead of an int.
Fix this trivial error by redefining irq as a signed int.  The
remaining consumers of the int are okay.

Signed-off-by: Prarit Bhargava &lt;prarit@redhat.com&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Cc: Sebastian Andrzej Siewior &lt;sebastian@breakpoint.cc&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Link: http://lkml.kernel.org/r/1389620420-7110-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
